Means for removing material in liquid form from tanks and the like



9, R M. SODEN MEANS FOR REMOVING MATERIAL IN LIQUID FORM E LI FROM TANKS AND TH KE y Filed May 27, 1955 2 Sheets-Sheet 1' lllt .5@

4 INVENTOR.-

ROBERT M. SODEN vBY ATTORNEY R. M. SODEN MEANS FOR REMOVING MATERIAL IN LIQUID FORM' July 9, 1957 FROM TANKS AND THE LIKE 2 Sheets-Sheet 2 Filed nay 27., v1955 j INVENTOR.

ROBERT M. SODEN ATTORNEY United States Patent M MEANS FR REMOVING MATERIAL 1N LIQUID FRM FROM TANKS ANH) THE LiKE Robert M. Soden, Washongal, Wash.

Application May 27, 1955, Serial Not 511,693

3 Claims. (Cl. 2S9--8) l This invention relates to the removal or draining off of thick or high density liquid from a container, and particularly material comprising substances in suspension in aliquid.

The invention relates especially to the removal of high density paper stock or pulp from large storage tanks, such as those in which the paper stock or pulp is customarily kept at paper mills.

The storage tanks used for this purpose at paper mills are generally made of reinforced concrete, lined with tile, and customarily are cylindrical with a conical or frustoconical bottom, with the outlet or discharge pipe located at the bottom of the tank.

When the pulp or paper stock is of the c-ustomary density of from l0 percent to l5 percent the stock will not flow out through the discharge pipe until the consistency of the stock is reduced. In order to enable proper Y flow to take place and to enable the stock lto be pumped effectively, the consistency must generally be reduced at least to percent or 6 percent. Consequently the customary practice has developed of reducing the density or consistency of the stock in the tank by the addition of water to the stock when the stock is to be discharged. Such addition of water to stock in a storage tank has heretofore customarily been accomplished through the medium of stationary nozzles located at various points in the tank wall through which the diluting water is delivered into the stock. Y

This customary manner of reducing stock consistency in order to facilitate withdrawal of stock from a storage tank presents several well known problems and disadvantages. One of the disadvantages is that, with ordinary large stock storage tanks, considerable time is required for reducing the consistency of the volume of stock in the tank to the point where satisfactory rate of ow from the tank and to the stock pump occurs. An average of one half hour has been required for securing such dilution in the kraft bleach storage tanks, of the customary size and capacity for kraft mills, to produce the desired rate of outflow.

Another and more serious difficulty has been the fact that there is always a considerable variation produced in the consistency of the stock as a result of the dilution of the stock in the tank in this manner. The consistency of the diluted stock has invariably been. found to be lower than actually was necessary and has generally averaged around 2 percent or 3 percent.

An object of the present invention is to provide improved and more eicient means for diluting and removing high density stock from storage tanks.

A more specic object of the invention is to provide improved means for diluting the stock as it is being removed from a storage tank or the like which will enable more substantial uniformity in the consistency of such diluted stock to be maintained;

A related `object is to `provide improved means for diluting and removing high density stock which will not necessitate a greater amount of dilution than is necessary or desirable.

A further object of the invention is to provide improved means for diluting high density stock in a storage tank 2,798,697 Patented July 9,v 1957 ICC which can be readily controlled and adjusted to suit particular conditions.

An additional object of the invention is to provide irnproved diluting means for high density liquid material in a tank which will be relatively inexpensive to manufacture and install, which will be practical, and which will involve no serious operational vor maintenance problems.

rlhe manner in which these objects are accomplished with the present invention and the manner in which the diluting and removing means is constructed and operates will be readily understood from the following brief description with reference to the accompanying drawings.

ln the drawings:

Figure l is a sectional elevation of a pulp storage tank showing the invention installed in operating position `in the same, the section being taken through the center of the lower por-tion of the tank;

Figure 2 is a fragmentary enlarged sectional elevation of the central portion of the tank bottom;

Figure 3 is an enlarged sectional elevation of the rotating nozzle head showing the two water-dispensing nozzles mounted in the same; and

Figure 4 is a plan section of the nozzle head taken on line 4 4 of Figure 3.

In Figure l the pulp storage tank 1) is of the usual cylindrical form with a frusto-conical bottom 11. The tank 10 is supported on a suitable base or supporting frame 12 'and is provided with the usual outlet pipe 13 in which a control valve 14 is mounted, the outlet pipe 13, however, being positioned off-center in the tank bottom.

A rotatable pipe section Ztl (shown most clearly in Figure 2) extends up through a central opening in the tank 10 through a leak-proof installation formed by a sealing plate 24 and suitable packing glands 24. The pipe section 26 is rotatably mounted in a supporting frame assembly indicated in general by the reference character 38 and this frame assembly is suspended below the tank bottom or is supported in any other suitable manner.

The bottom end of the rotatable pipe section 2d has a rotary joint connection 21 with a water delivery pipe 15.

Rotation of the pipe section 20 is produced through the medium of a gear 22 which is secured on the pipe section 20 and which meshes with a pinion driven from an electric motor 23.

Water from a suitable external source is conveyed through pipe 19 (Figure l) to a pump 17 which is operated by a motor 18. The pump 17 delivers water under pressure through the pipe 15 and thence to the rotatable pipe section 20. The delivery of the water into the rotatable pipe 4section 26 is controlled by a valve 16 located in pipe 15 as well as by the speed of the motor 18 and pump 17.

A water-distributing head or nozzle head 25 is secured to the top end of the rotatable pipe section Et and is located a short distance above the tank bottom in thc relative position indicated in Figures l. and 2. PrefA erably this water-distributing head is cylindrical in shape and may conveniently be fabricated as illustrated in Figure 3, from a short piece of pipe having at least twice the diameter of the pipe section 2d. The top end of the head 25 is closed by a top plate 26 which is welded to the cylindrical wall of the head, and thefbottorn of the head is formed by an annular plate 27 secured to the cylindrical wall and with a threaded neck 28 secured to the annular plate 27. The threaded neck 28 enables the head to be rmly secured on the threaded top end of the pipe section 29. Bottom brace members 33 are joined to the threaded neck 2S, annular plate 27 and cylindrical wall in order to provide additional reinforcement.

tank. The discharging mouths of these nozzles are on diametrically opposite sides of the head and are positioned at different heights above the bottom of the tank. Thus, as the nozzle headv is rotated, the diluting water from these nozzles is thoroughly distributedl over areas of pulp at different levels in the lower portion of the tank.

Preferably, although not necessarily, the two nozzles 29 and 31 are contained entirely within the head 25, as shown, the discharging mouths of the nozzles being located in the cylindrical wall of the head. This reduces the likelihood of any whirlpool action or similar agitation beingset up in the stock in the bottom of the tank as a result of the rotation of the head, foranysuch excessive agitation might cause the diluting water to be distributed less thoroughly or effectively.

It will be noted also from Figure 3 that the upper nozzle 29 is positioned with its axis horizontal while the axis of the lower nozzle 31 is inclined downwardly at a slight angle (for example 5) from the horizontal. Thus the jets of diluting water enter the stock in the tank along the direction lines indicated by the two rows of arrows respectively, shown in Figure 2. The downwardly inclined direction in which the jet from the lower nozzle is discharged prevents any possibility of the stock located along the bottom of the tank escaping from the diluting effect of the water from the lower nozzle jet.

Preferably, but not necessarily, the discharging mouths of both nozzles are of the same diameter and the diameters of the intake ends of the two nozzles also are approximately equal. However, I consider it preferable in such case to have the lower nozzle 31 made shorter in length than the upper nozzle 29, as shown in the drawings. With this arrangement a slightly greater amount of diluting water will be discharged from the lower nozzle than from the upper nozzle. Since the reason for diluting the stock is to enable the stock to flow more readily through the discharging pipe 13 of the tank, the delivery of the diluting water from the lower nozzle into the bottom of the tank immediately alects the consistency of the stock as it is about to leave the tank. Thus the rate at which such diluting water is discharged from the lower nozzle is of particular importance in controlling the consistency and rate of outflow of the stock. Any change inthe rate at which water is delivered through the pipe into the nozzle head 25 will have its most immediate effect on the jet from the lower nozzle 31 and thus on the consistency of the stock leaving the tank, and this, in turn, enables the consistency of the stock as discharged from the tank to be more carefully controlled.

The nozzles 29 and 31 are mounted securely in the nozzle head in any satisfactory manner. Thus, for example, the upper nozzle 29 (Figures 3 and 4) is shown secured in place by means of side brackets 36 and 37 and a bottom support bracket 30; while the lower nozzle 31 is similarly secured by side brackets 34 and 35 and an upper bracket 32.

Various modifications could, of course, be made in the actual construction of the nozzle head, or in related parts of the device, without departing from the principle 0f the invention, but the particular construction which I have illustrated and described I have found to be very satisfactory in actual practice and accordingly I regard this as the preferred form for the carrying out of my invention.

By providing adequate rotating speed for the nozzle head 25, by careful control and regulation of the rate at which the distributing Water is delivered to the nozzle head, and by testing the consistency of the stock, from time to time, which is delivered from the tank, an adequate rate of outow of the stock can be maintained while at the same time excessive dilution can be avoided and the consistency maintained within reasonable and desirable I claim:

l. The combination of a tank containing dilutable material, an outlet pipe in the bottom of said tank, a control valve for said outlet pipe, a nozzle head rotatably mounted in the bottom of said tank and centrally located therein, means for delivering liquid under pressure into said head from outside of said tank, control means in said liquid delivery means, means for rotating said nozzle head, a pair of nozzles on said head, said nozzles positioned at different heights above said bottom of said tank, said lower nozzle so constructed as to deliver a slightly greater volume of liquid into said tank than said upper nozzle, whereby the diluting liquid from said rotating head will be thoroughly distributed in the material in the bottom portion of said tank and whereby the extentl of dilution of the material discharged from said tank can be controlled by controlling the rate at which the diluting liquid is delivered' to said head.

2. The combination of a tank containing dilutable material, an outlet pipe located 'olf center in the bottom of said tank, a control valve for said' outlet pipe, a nozzle head rotatably mounted in the bottom of said tank and centrally located therein, said nozzle head having a liquidreceiving chamber, means for delivering liquid under pressure intol said chamber from outside of said tank, control means in said liquid delivery means, means located outside of said tank for rotating said nozzle head, a pair of nozzles supported in said ychamber and extending through the outside wall of said chamber, said nozzles extending radially in diametrically opposite directions from the axis of said head, said nozzles positioned at different heights above said bottom of said tank, the axis of said upper nozzle being substantially horizontal, and the axis of said lower nozzle having a slight inclination downwardly, the discharging mouths of said nozzles being of substantially the same diameter, but said lower nozzle being of shorter length than said upper nozzle, whereby the diluting liquid from said rotating head will be thoroughly distributed in the material in the bottom portionr of said tank and whereby the extent of dilution of the material discharged from said tank can be controlled by controlling the rate at which the diluting liquid is delivered to said head.

3. The combination of a tank containing dilutable material, an outlet pipe located off center in the bottom of said tank, a control valve for said outlet pipe, a nozzle head rotatably mounted in the bottom of said tank andy centrally located therein, said nozzle head having a waterreceiving chamber, means for delivering water under pressure into said chamber from outside of said tank, control means in said water delivery means, means located outside of said tank for rotating said nozzle head, a pair of nozzles supported in said chamber and terminating on the outside of the outside wall of said chamber, said nozzles extending radially in diametrically opposite directions from the axis of said head, said nozzles positionedl at different heights above said bottom of said tank, the axis of said upper nozzle being substantially horizontal, andthe axis of said lower nozzle having a slight inclination downwardly,y said lower nozzle constructed to. deliver a slightly greater volume of water than said upper nozzle, whereby the diluting water from said rotating head will be thoroughly distributed in the material in the bottom portion of said tank andi wherebyl theY extent of dilution of the` material discharged from saidV tank can be controlled by controlling the rate at which the diluting Water is delivered to said-head.

References Cited in the tile of this, p atent UNITED STATES PATENTS 8363717r Trent Nov. 27, 1906I 1..526 ,59,6,- Greenawalt Y.Y V Feb. 1 7, 1925 2,118.908 Vermillion May 3l, 1938 

